Dear Steve, Thank you for sharing info. Azure Information Protection Viewer prevent us from download.
The feature of update document, SharePoint versioning will be lost. (File will not be sync with SharePoint Libraries - In case file update, change or remove.) AIP force us to download file, we have requirement to access file directly from SharePoint list without download with security and access file in Real mode. If admin delete file from Library user will not be able to view document.